This invention relates generally to the field of harvesting combines and, in particular, to an improved apparatus for feeding grain to the clean grain elevator.
Combines are used to harvest agricultural crops such as corn, soybeans, wheat and other grain crops. As the combine is driven through the crops, the combine cuts the crop, separates the desired crop from the undesired waste, stores the crop, and discards the waste.
In a typical combine, a head is mounted to the front of the combine to gather the crop and feed the crop into the combine for processing. As the combine is driven through the field, the crop material is collected by the head and deposited into a feeder housing. The crop material is then transported upwardly and into the combine by a feed elevator located within the feeder housing. The crop material then passes through a threshing and separating mechanism. In a rotary combine, the threshing and separating mechanism comprises a rotor, a threshing concave, a rotor cage, and a separating grate. As crop material passes between the rotor, the threshing concave and the separating grate, the crop material is impacted and/or rubbed, thereby causing the grain to separate from stalk material. The stalk material that is separated from the grain is called MOG (material other than grain).
After passing through the threshing and separating assembly, the grain and MOG are deposited on to a grain cleaning system. The grain cleaning system of a typical combine comprises a pair of adjustable cleaning sieves, often referred to as a chaffer sieve and a shoe sieve. The sieves are typically reciprocated back and forth in opposite directions along an arcuate path. This motion has the tendency to separate the grain from the MOG. To further separate the grain from the MOG, a cleaning fan or blower is positioned so as to blow air up through the cleaning sieves. This flow of air tends to blow the MOG, which is typically lighter than grain, rearwardly and out the back of the combine. Grain, which is heavier than MOG, is allowed to drop through the openings in the sieve.
The clean grain that falls through the cleaning sieves is deposited on a collection panel positioned beneath the cleaning sieves. The collection panel is angled so as to permit the grain to flow, under the influence of gravity, into an auger trough positioned along the lowermost edge of the collection panel. The auger trough is typically positioned near the forward end of the cleaning sieves and extends along the width of the sieves. The grain collected in the auger trough is then moved by an auger towards the side of the combine where it is raised by a grain elevator and deposited into a storage tank.
The grain collecting auger comprises an axle or shaft about which a blade (called the auger flighting) is spirally positioned. As the collecting auger is rotated, the flighting moves the grain along the length of the auger and into the base or boot of the grain elevator. The grain elevator typically comprises a housing having a series of paddles attached to a continuous chain. The chain is connected between a pair of sprockets located inside the top and bottom, respectively, of the elevator housing. As the chain is driven, the grain collected in the boot of the elevator is lifted up through the elevator housing by the paddles. A separate auger then moves the grain from the top of the elevator housing into a storage tank on the combine.
In a typical combine, the lower sprocket of the grain elevator is supported on the shaft of the collecting auger. This arrangement has a number of disadvantages. For example, the grain that is fed into the elevator boot by the collecting auger must pass around the face of the elevator lower sprocket. The sprocket consequently obstructs and limits the flow of the grain into the elevator boot. The portion of the chain wrapped about the lower sprocket similarly obstructs the flow of grain. This arrangement also tends to disproportionately load grain onto the ends of the elevator paddles adjacent to the collecting auger trough, thereby limiting the amount of grain that can be raised up through the grain elevator by the paddles. In addition, both obstructions tend to damage grain flowing past them.
In addition, combines are being designed to harvest increasingly larger volumes of crop. These larger volume combines have correspondingly larger grain cleaning systems. In particular, the grain cleaning systems on these larger combines utilize longer cleaning sieves, and consequently, a longer grain collection panel. As the collection panel increases in length, the angle of the panel relative to the ground decreases, thereby inhibiting the flow of clean grain (under the influence of gravity) into the grain collection trough. Moreover, the increased volume of grain being collected necessarily requires a larger grain collection trough and auger. Increasing the size of these components further limits the angle of the collection panel, which must necessarily be positioned above the bottom of the collection trough.
Accordingly, it would be desirable to provide an apparatus for collecting the grain from beneath the grain cleaning system and moving the grain into the grain elevator that overcomes the disadvantages and limitations described above.
The present invention provides an offset auger feed assembly for use with a grain harvesting combine. In particular, the offset auger feed assembly provides an improved apparatus for feeding grain into a grain elevator, which is used to lift the grain into a storage tank on the combine. The grain elevator encloses a plurality of paddles connected to a continuous chain. Sprockets located at the top and bottom of the grain elevator support the continuous chain. As the chain is driven, the paddles scoop-up and lift any grain that has been collected in the bottom of the grain elevator, commonly referred to as the boot.
The grain is fed into the boot by an auger assembly. The auger assembly comprises an auger trough connected to the boot. An auger is positioned in the auger trough. As the auger is rotated, any grain in the trough is moved along the trough and through an opening in the side of the boot. The shaft of the auger is offset from lower sprocket that supports the continuous chain at the bottom of the grain elevator. This offset permits the grain to be fed into the boot without having to pass around the lower sprocket or the continuous chain, both increasing capacity and reducing grain damage. The offset also permits the grain to fed more evenly along the entire length of the paddles, thereby increasing the volume of grain that can be lifted by the grain elevator.
Another aspect of the invention includes a tapered portion on the elevator boot. The tapered portion provides a transition area for the grain being fed into the boot by the auger. In particular, the tapered portion directs the flow of grain entering the boot from the auger trough towards the paddles, and insures that the grain is evenly distributed along the entire length of the paddles.
The preferred embodiment of the invention includes features in addition to those listed above. Moreover, the advantages over the current art discussed above are directly applicable to the preferred embodiment, but are not exclusive. The other features and advantages of the present invention will be further understood and appreciated when considered in relation to the detailed description of the preferred embodiment.